SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9bcf55071b0bac3f23367797dc255cc916be8ef14de858f66368dc284c93bd1' 
  AND token = 'jCVR6Q8zK8GkkGIZQYx5I5fq56qrgoPJPWTFcpH12kM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}